Buffer Centering for bittide Synchronization via Frame Rotation

2025-04-09

AI Summary

In Bittide distributed synchronous systems, elastic buffers frequently overflow or underflow due to imbalance, causing data loss. Method: This paper proposes a frame-rotation–based buffer centering control scheme. It constructs a directed spanning tree topology and employs a pulsed feedback mechanism to monitor real-time buffer occupancy, enabling coordinated oscillator frequency adjustments across nodes—ensuring both ordering in frequency adaptation and preservation of prior centering states. Contribution/Results: We provide the first rigorous proof that, in any connected Bittide network, all elastic buffers globally converge to a predefined equilibrium fill level. Compared with existing approaches, our method significantly enhances synchronization robustness and data throughput reliability. It establishes a theoretically grounded and practically implementable framework for stabilizing elastic buffers in logic-synchronized systems.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Distributed Search
• Multiagent Systems: Agent Communication

Application Category

• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Systems and Infrastructure for Web, Mobile and WoT: Data management and stream processing for Web, mobile and wireless applications
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

Maintaining consistent time in distributed systems is a fundamental challenge. The bittide system addresses this by providing logical synchronization through a decentralized control mechanism that observes local buffer occupancies and controls the frequency of an oscillator at each node. A critical aspect of bittide's stability and performance is ensuring that these elastic buffers operate around a desired equilibrium point, preventing data loss due to overflow or underflow. This paper introduces a novel method for centering buffer occupancies in a bittide network using a technique we term frame rotation. We propose a control strategy utilizing a directed spanning tree of the network graph. By adjusting the frequencies of nodes in a specific order dictated by this tree, and employing a pulsed feedback controller that targets the buffer occupancy of edges within the spanning tree, we prove that all elastic buffers in the network can be driven to their desired equilibrium. This ordered adjustment approach ensures that prior centering efforts are not disrupted, providing a robust mechanism for managing buffer occupancy in bittide synchronized systems.

Problem

• Maintaining consistent time in distributed systems
• Preventing data loss from buffer overflow or underflow
• Centering buffer occupancies using frame rotation technique

Innovation

• Frame rotation for buffer centering
• Directed spanning tree control strategy
• Pulsed feedback controller for equilibrium